scholarly journals Drought Stress Impairs Communication Between Solanum tuberosum (Solanales: Solanaceae) and Subterranean Biological Control Agents

2019 ◽  
Author(s):  
Mahnaz Hassani-Kakhki ◽  
Javad Karimi ◽  
Fahim El Borai ◽  
Nabil Killiny ◽  
Mojtaba Hosseini ◽  
...  
Keyword(s):  
Drought Stress ◽  
Abiotic Factors ◽  
Crop Protection ◽  
Control Plant ◽  
Tritrophic Interaction ◽  
Plant Roots ◽  
Soil Matrix ◽  
Diaprepes Abbreviatus ◽  
Root Herbivory ◽  
Potato Plants

Abstract The attraction of entomopathogenic nematodes (EPNs) to herbivore-injured plant roots has been documented recently to be a common tritrophic interaction. Belowground tritrophic interactions are especially subject to modulation by many abiotic factors including drought. In this study, complementary greenhouse experiments were conducted to understand how drought stress might affect a potato plant’s impact on EPN behavior. In separate trials, the responses of the EPN Steinernema diaprepesi (Nguyen and Duncan) (Rhabditida: Steinernematidae) to root herbivory by larvae of the weevil Diaprepes abbreviatus (Linnaeus) (Coleoptera: Curculionidae), in well-watered and drought stressed potato plants, were measured using soil-matrix olfactometers with two arms. The drought treatments were initiated in 30-d old plants. Drought-stressed potato plants received water when potentiometers read approximately 20 kPa, while for well-watered plants, the number was 8 kPa. Four weeks after initiating the treatments, 400 ml water was added to all pots, immediately before starting the experiments. The experiments revealed that S. diaprepesi infective juveniles (IJs) did not migrate preferentially toward drought-stressed or well-watered plants when neither were subjected to herbivory [t(21) = 1.13, P = 0.269]. However, plants with roots damaged by herbivory attracted more S. diaprepesi IJs if they were well watered than if they were drought stressed [t(24) = 3.19, P = 0.004]. If both plants in the olfactometers were drought stressed, EPNs moved preferentially toward those with root herbivory than those with undamaged roots [t(23) = 3.19, P = 0.004]. No difference was detected in gas chromatography profiles between droughted and well-watered plant roots subjected to herbivory [F(24, 336) = 0.68, P = 0.87]. GC analysis showed that three compounds, including 3-nonanone [t(6) = 4.83, P = 0.003], artemisyl ketone [t(7) = 6.21, P = 0.000], and benzoic acid, 4-ethoxy-, ethyl ester [t(7) = −4.22, P = 0.004] were significantly higher in drought stressed than control plant roots. These results indicate that potatoes, like other plants, can recruit EPNs in response to root herbivory, and that drought stress dampens this tritrophic interaction where choice is involved. Additional research that resolves the mechanisms of these interactions may provide insights to exploit EPNs for crop protection.

Respon Morfologis dan Ekspresi Gen Aquaporin pada Padi IR 64 yang Mengalami Cekaman Kekeringan pada Fase Reproduktif (Morphological Responses and Aquaporin Gene Expression in Rice IR64 under Drought Stress at the Reproductive Stage)

2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Made Pharmawati ◽  
Ni Nyoman Wirasiti ◽  
Luh Putu Wrasiati
Keyword(s):  
Gene Expression ◽  
Drought Stress ◽  
Real Time ◽  
Real Time Pcr ◽  
Control Plant ◽  
Reproductive Stage ◽  
Limiting Factors ◽  
Rice Grain ◽  
Aquaporin Gene ◽  
Peg Treatment

Abstrak Cekaman kekeringan merupakan faktor pembatas penting bagi pertumbuhan dan produktivitas tanaman termasuk padi.      Penelitian ini bertujuan menganalisis respon padi IR64 terhadap cekaman kekeringan dengan pemberian polietilen glikol (PEG) pada fase reproduktif.  Penelitian juga bertujuan menganalisis ekspresi gen aquaporin akibat cekaman kekeringan.  Bibit padi ditanam dalam pot dan perlakuan PEG dengan konsentrasi 108g/L (-0.25MPa) dan 178g/L (-0.52 MPa) diberikan saat munculnya panikula. Perlakuan diberikan selama 2 minggu, kemudian tanaman disiram kembali.  Ekspresi gen diamati pada akhir perlakuan dengan semi kuantitatif real time PCR.  Ekstraksi RNA menggunakan RNeasy plant mini kit, sedangkan sintesis cDNA menggunakan Transcriptor First Strand cDNA Kit.  Hasil penelitian menunjukkan bahwa jumlah malai dan berat total malai berkurang akibat cekaman kekeringan.  Persentase gabah kosong mencapai 84,6% pada perlakuan PEG-0,52 MPa, sedangkan pada perlakuan PEG -0,25 MPa persentase gabah kosong sebesar 67,8%.  Pada kontrol persentase gabah kosong adalah 10,3%.  Ekspresi gen OsPIP2;7 sedikit menurun pada perlakuan PEG -0,52 MPa.Kata kunci: ekspresi gen, IR64, kekeringan, padi, PEG  Abstract Drought stress is one of the limiting factors of plant growth and productivity including rice.  The aim of this study was to analyze responses of IR64 rice to polyethylene glycol (PEG)-induced-drought stress at the reproductive stage.  This study also aimed to analyze the expression of aquaporin under drought stress.  Rice seedlings were grown in pot system and PEG treatment at concentration of -0.25MPa (108g/L) and -0.52 MPa (178g/L) were given when the panicles arose.  Treatments were conducted for 2 weeks, after that the plants were rewatered.  Gene expression was evaluated at the end of PEG treatment using semi quantitative real time PCR. RNA was extracted using RNeasy plant mini kit, while cDNA synthesis was done using Transcriptor First Strand cDNA Kit.  The results showed that the number and weight of rice ear were less in plant treated with PEG than in control.  The percentage of empty rice grain reached 84.6% at PEG -0.52 MPa, while at PEG -0.25 MPa the percentage of empty grain was 67.8%.  In control plant, the percentage of empty grain was 10.3%.  Drought stress did not alter the expression of OsPIP2;7.  Keywords: drought, gene expression, IR64, PEG, rice

scholarly journals Black Root Rot Caused by Thielaviopsis basicola on Lettuce in California

Plant Disease ◽  
2008 ◽  
Vol 92 (9) ◽  
pp. 1368-1368 ◽  
Author(s):  
S. T. Koike
Keyword(s):  
Root Rot ◽  
Disease Incidence ◽  
Control Plant ◽  
Pathogenic Fungi ◽  
Plant Roots ◽  
Peat Moss ◽  
Thielaviopsis Basicola ◽  
Black Root Rot ◽  
Iceberg Lettuce ◽  
Salinas Valley

In 2005 and 2006, field-grown iceberg lettuce (Lactuca sativa) in California's coastal Salinas Valley (Monterey County) was affected by a previously unreported disease. Symptoms were observed on iceberg lettuce at the post-thin rosette stage (8 to 12 leaves). Plants were stunted and slightly chlorotic. Fine feeder roots had numerous, small (4 to 8 mm long), elongated, dark brown-to-black lesions. Larger secondary roots and taproots lacked lesions. No vascular discoloration was present. Isolations from root lesions consistently resulted in gray fungal colonies that formed catenulate, cylindrical, thin-walled, hyaline endoconidia and catenulate, subrectangular, thick-walled, dark aleuriospores. The fungus was identified as Thielaviopsis basicola (2). Conidial suspensions (5.0 × 105) of eight isolates from iceberg lettuce were used for pathogenicity tests. Iceberg cv. Ponderosa and romaine cv. Winchester were grown for 3 weeks in soilless peat moss rooting mix. Roots of 20 plants per cultivar were washed free of the rooting mix and soaked in conidial suspensions for 5 min. Plants were repotted and grown in a greenhouse. Control plant roots were soaked in sterile distilled water (SDW). After 3 weeks, inoculated iceberg exhibited slight chlorosis in comparison with control plants. Feeder roots of all iceberg plants inoculated with the eight isolates exhibited numerous black lesions and T. basicola was reisolated from these roots. Romaine lettuce, however, did not show any foliar symptoms. Small segments of roots had tan-to-light brown discoloration and T. basicola was occasionally reisolated (approximately 40% recovery). Roots of control iceberg and romaine showed no symptoms. Results were similar when this experiment was repeated. To explore the host range of T. basicola recovered from lettuce, two isolates were prepared and inoculated as described above onto 12 plants each of the following: iceberg lettuce (cv. Ponderosa), bean (cv. Blue Lake), broccoli (cv. Patriot), carrot (cv. Long Imperator #58), celery (cv. Conquistador), cotton (cv. Phy-72 Acala), cucumber (cv. Marketmore 76), green bunching onion (cv. Evergreen Bunching), parsley (cv. Moss Curled), pepper (cv. California Wonder 300 TMR), radish (cv. Champion), spinach (cvs. Bolero and Bossanova), and tomato (cv. Beefsteak). Control plant roots of all cultivars were soaked in SDW. After 4 weeks, only lettuce and bean roots had extensive brown-to-black lesions, from which the pathogen was consistently resiolated. Roots of cotton, pepper, spinach, and tomato had sections of light brown-to-orange discoloration; the pathogen was not consistently recovered from these sections. All other species and the control plants were symptomless. This experiment was repeated with similar results except that inoculated peppers were distinctly stunted compared with control plants. To my knowledge, this is the first report of black root rot caused by T. basicola on lettuce in California. Disease was limited to patches along edges of iceberg lettuce fields; disease incidence in these discrete patches reached as high as 35%. Affected plants continued to grow but remained stunted in relation to unaffected plants and were not harvested. Black root rot of lettuce has been reported in Australia (1); that report also showed that lettuce cultivars vary in susceptibility to T. basicola and isolates from lettuce were highly aggressive on bean but not on many other reported hosts of this pathogen. References: (1) R. G. O'Brien and R. D. Davis. Australas. Plant Pathol. 23:106, 1994. (2) C. V. Subramanian. No. 170 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1968.

Weed Science in a Crop Protection Program

Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 74-76
Author(s):  
Leo E. Bendixen ◽  
D. E. Herr ◽  
E. W. Stroube ◽  
E. K. Alban ◽  
A. C. Waldron
Keyword(s):  
Plant Disease ◽  
Focal Point ◽  
Graduate Training ◽  
Crop Protection ◽  
Control Plant ◽  
Pesticide Analysis ◽  
Weed Science ◽  
Application Management ◽  
Plant Disease Control ◽  
Control Insect

An increasingly urgent need exists for men, broadly yet specifically, trained in the areas of crop protection. Crop protection includes weed control, insect control, plant disease control, and pesticide analysis. The need extends across teaching, research, development, sales, application, management, and other areas encompassed by crop protection. Administrative and financial advantages may result from the development of this type of program. Curricula for the BS, MS, and PhD degrees have been developed which offer a broad base of crop protection but allow pursuit of the degree from (or specialization in) any of the areas of crop protection. At the same time, however, chemistry and physiology form the disciplinary basis of all science curricula and the focal point is graduate training. Four courses relevant to all areas of crop protection and five additional courses in weed science have been developed.

Crop Protection Under Drought Stress

2020 ◽  
pp. 145-170
Author(s):  
Ram L. Ray ◽  
Peter A. Y. Ampim ◽  
Ming Gao
Keyword(s):  
Drought Stress ◽  
Crop Protection

Expression of Arabidopsis HOMEODOMAIN GLABROUS 11 Enhances Tolerance to Drought Stress in Transgenic Sweet Potato Plants

2011 ◽  
Vol 55 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Long Ruan ◽  
Lijuan Chen ◽  
Yihong Chen ◽  
Jinling He ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Sweet Potato ◽  
Potato Plants

scholarly journals Transcriptomic studies reveal a key metabolic pathway contributing to a well-maintained photosynthetic system under drought stress in foxtail millet (Setaria italica L.)

2018 ◽  
Author(s):  
Weiping Shi ◽  
Jingye Cheng ◽  
Xiaojie Wen ◽  
Jixiang Wang ◽  
Guanyan Shi ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Abiotic Factors ◽  
Chlorophyll Biosynthesis ◽  
Foxtail Millet ◽  
Setaria Italica ◽  
Parental Lines

Drought stress is one of the most important abiotic factors limiting crop productivity. A better understanding of the effects of drought on millet (Setaria italica L.) production, a model crop for studying drought tolerance, and the underlying molecular mechanisms responsible for drought stress responses is vital to improvement of agricultural production. In this study, we exposed the drought resistant F1 hybrid, M79, and its parental lines E1 and H1 to drought stress. Subsequent physiological analysis demonstrated that M79 showed higher photosynthetic energy conversion efficiency and drought tolerance than its parents. A transcriptomic study using leaves collected six days after drought treatment, when the soil water content was about ~20%, identified 3066, 1895, and 2148 differentially expressed genes (DEGs) in M79, E1 and H1 compared to the respective untreated controls, respectively. Further analysis revealed 17 Gene Ontology (GO) enrichments and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in M79, including photosystem II (PSII) oxygen-evolving complex, peroxidase (POD) activity, plant hormone signal transduction, and chlorophyll biosynthesis. Co-regulation analysis suggested that these DEGs in M79 contributed to the formation of a regulatory network involving multiple biological processes and pathways including photosynthesis, signal transduction, transcriptional regulation, redox regulation, hormonal signaling, and osmotic regulation. RNA-seq analysis also showed that some photosynthesis-related DEGs were highly expressed in M79 compared to its parental lines under drought stress. These results indicate that various molecular pathways, including photosynthesis, respond to drought stress in M79, and provide abundant molecular information for further analysis of the underlying mechanism responding to this stress.

scholarly journals Transcriptomic studies reveal a key metabolic pathway contributing to a well-maintained photosynthetic system under drought stress in foxtail millet (Setaria italica L.)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4752 ◽  
Author(s):  
Weiping Shi ◽  
Jingye Cheng ◽  
Xiaojie Wen ◽  
Jixiang Wang ◽  
Guanyan Shi ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Abiotic Factors ◽  
Chlorophyll Biosynthesis ◽  
Foxtail Millet ◽  
Setaria Italica ◽  
Parental Lines

Drought stress is one of the most important abiotic factors limiting crop productivity. A better understanding of the effects of drought on millet (Setaria italica L.) production, a model crop for studying drought tolerance, and the underlying molecular mechanisms responsible for drought stress responses is vital to improvement of agricultural production. In this study, we exposed the drought resistant F1 hybrid, M79, and its parental lines E1 and H1 to drought stress. Subsequent physiological analysis demonstrated that M79 showed higher photosynthetic energy conversion efficiency and drought tolerance than its parents. A transcriptomic study using leaves collected six days after drought treatment, when the soil water content was about ∼20%, identified 3066, 1895, and 2148 differentially expressed genes (DEGs) in M79, E1 and H1 compared to the respective untreated controls, respectively. Further analysis revealed 17 Gene Ontology (GO) enrichments and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in M79, including photosystem II (PSII) oxygen-evolving complex, peroxidase (POD) activity, plant hormone signal transduction, and chlorophyll biosynthesis. Co-regulation analysis suggested that these DEGs in M79 contributed to the formation of a regulatory network involving multiple biological processes and pathways including photosynthesis, signal transduction, transcriptional regulation, redox regulation, hormonal signaling, and osmotic regulation. RNA-seq analysis also showed that some photosynthesis-related DEGs were highly expressed in M79 compared to its parental lines under drought stress. These results indicate that various molecular pathways, including photosynthesis, respond to drought stress in M79, and provide abundant molecular information for further analysis of the underlying mechanism responding to this stress.

scholarly journals The Effectiveness of Endophytic Fungi Origin of Potato Plant Roots in Coffee Skin Compost Media to Suppress Development of Potato Leaf Disease (Phytophtora infestans)

2020 ◽  
Vol 2 (1) ◽  
pp. 101-105
Author(s):  
Anna Fitriana ◽  
Lukman Hakim ◽  
Marlina Marlina
Keyword(s):  
Experimental Method ◽  
Endophytic Fungi ◽  
Potato Plant ◽  
Potato Production ◽  
Leaf Blight ◽  
Plant Roots ◽  
Potato Leaf ◽  
Potato Plants ◽  
Pathogen Attack ◽  
Blight Disease

Potato leaf blight is caused by Phytophthora infestans fungus is one of the important diseases in potato plants. The decrease in potato production due to P. infestans can reach 90%. Until now, P. infestans pathogen attack is an important problem and there is no fungicide that is really effective against the disease. This study aims to examine the effectiveness of endophytic fungi from potato roots in suppressing the development of P. infestans potato leaf blight disease carried out at University Farm Stasiun Riset Bener Meriah (UFBM) Syiah Kuala University Tunyang Village, Timang Gajah District, Bener Meriah Regency from May to October 2014. The method used is the experimental method. The results of this study indicate that endophytic fungi from the roots of potato plants in coffee skin compost media can suppress the development of leaf blight caused by P. infestans, endophytic fungi from potato plant roots in coffee skin compost media. The best results were found in B9 endophytic fungi isolates with the intensity of the pathogen attack P. infestans 48.00%, the intensity of damage to potato plants due to pathogen P. infestans and 2.60%, the weight of healthy tubers 332.4 grams.

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